Commutator testing and sorting device



Sept. 9, 1952 R. c. WHELCHEL COMMUTATOR TESTING AND SORTING DEVICE 14 Sheets-Sheet 1 Filed April 17, 1948 THERMHL RELNY R. C. WHELCHEL.

COMMUTATOR TESTING AND SORTING DEVICE Sept. 9, 1952 Filed April 17, 1948 14 Shets-Sheet 2 Sept. 9, 1952 R. c. WHELCHEL 2,609,927

'COMMUTATOR TESTING AND SORTING DEVICE Filed April 17, 1948 14 Sheets-Sheet 5 P 9, 1952 R. c. WHELCHEL 2,609,927'

COMMUTATOR TESTING AND SORTING DEVICE Filed April 17; 1948 1,4 Sheets-Sheet 4 Sept. 9, 1952 RC. WHELCHEL 2,609,927

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Sept. 9, 1952 R. c. WHELCHEL COMMUTATOR TESTING AND SORTING DEVICE l4 Sheets-Sheet 7 Filed April 17, 1948 611v E TOR Sept. 9, 1952 R. c. WHELCHEL 2,609,927

COMMUTATOR TESTING AND SORTING DEVICE Filed April 17, 1948 14 Sheets-Sheet 8 @WZM P 9, 1952 R. c. WHELCHEL 2,609,927

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p 9, 1952 R. c. WHELCHEL COMMUTATOR TESTING AND SORTING DEVICE l4 Sheets-Sheet 14 Filed April 17, 1948 INVENTOR. g w iffloz Patented Sept. 9, 1952 COMMUTATOR TESTING AN D. SORTIN G DEVICE RupertC. Whelchel, Anderson, Ind., assi nor to General Motors. Corporation, Detroit, Mich.,"a

. corporation of Delawarc .ApplicationaApril 17, 1948, Serial No. 21,730

6 Claims.

This invention relatesto :the. manufacture of 'commutators usedwith direct current to dynamoelectricr'machines. andits. object is to provide apparatus forsdetecting. a'short circuitbetween any adjacentrcommutator bars. and between any bar and-core ofthe commutator. The apparatus provides achutealong which the commutators pass to a firstistation where the commutator stops and is rotated and: current is applied for the purpose of burning oii'nmetal particles clinging between adjacent bars. in order that such particles would not interfere with a true test of permanent short circuit. "At the second. station to whichthe com- :mutator; passes,it is stopped. and rotated while scurrent zlis applied to it to test for shorts or grounds. If there is ashort between-bars, a trap- 'isautomatically sprung to divert thecommutator 'intoraizbin for receiving shorted commutators. .Iithereis: a: ground between a bar. and the core,

xa-notheritrap is automatically sprung which di- 'Fig. B isa' sectional view on line 3-3 of Fig. 6. "Figmi-ui r arside'viewsora portion of the track ou -which.thecommutators r011 after'having been inspected.

Fig ciA'is a view in thedirection-of arrow 4A fJEigjA. l

Fig.:"5.:.is"a .fragmentary'view in the direction ofarrow 5 of Fig.1 6.

"Fignfi is'afviewxin theidirection of the arrow Figs. 7; and 8; taken togethenconstitute a front elevation of the inspecting machine.

.i-Fig; 91s a view in the direction of arrow 9 of Figs. 7. and 8.

Fig. 10 is a viewin the direction of arrow [0 of Fig: 9.

Figs. 11v and 12 are sectional views on lines H-lr and l2-l2 of Fig. 10 and are drawn'to ta clargen scale.

--Fig.-.l3-is asectional view on line I3-I3 of .Fig. 11.

Figs. Hand 15 are sectional views, respectively, on lines iii-[land I 5-15 of Fig.-1O and are drawnto a larger scale.

Fig. 16 is. a sectional view nline l6-l6 of Fig. 10 and. are drawn toa larger scale.

Fig. 17 is a sectional view on. line lT-Il of Fig. 9 and are drawn toa larger scale.

Fig. 18 is a view in the direction .of arrow. N3 of Fig. 17.

Fig. 19. is an enlarged sectional view taken on line Ill-I9 of Fig. 10.

Fig. 20 is a sectional view onlineZfl-ZU of Fig. 19. p a

Fig- 21 is an enlarged sectional view online 2l-2l of Fig.10.

Fig.22 is a sectional view on line- 22-22 of Fig. 21.

Fig. 23 isa view in the. directionzoi arrow. 23 of Fig. 21.

Fig. 24 is an. enlarged sectional view on line 24-24 of Fig. 10.

Figs; 25 and 27. are sectional views respectively on lines 25-25and2'I-21 of Fig. 24.

Fig. 26 is a View in the. direction of arrow 26 of Fig. 24..

Fig. 28 is an enlarged sectional view and taken on line 28-28 ofFig. 10.

Figs. 29and 30. are sectional views respectively on lines 29-29. and 30-30of'liig. 28.

Fig. 30Aisa sectional view on .line 30A-36A of Fig. 30.

Fig.31 is a view in the direction. of arrowil of Fig. 28.

Fig. 32 is a cam chart.

Figs-33, 34 and 35 arefront, top and side views respectively of' an. attachment forfeedingcommutators having riser bars.

Referring to Figs. 7. and 3, the track down which the .commutators C, roll is made in two sections 40 and. jTracksection40 comprises bars 43' and 44 which'screws'45 and dowels 45a connect. to a vertical plate lfi' (Figs. Hand 12). Plate 46 is attachedas shown inFigglZ to a base 50, which as shown in Fig. 9, is supported above a plate 5| by posts 52. Plate.5l may rest upon the floor or may be supported above it in any suitable manner, not. shown. Braces 46a are attached to table 50.and plate',46.

Base 5! supports the housing53 of a speed reducing mechanism which is connected with an electric motor 55. .The output shaft54 .ofthe speed reducer is connected with .asproclret. 56

sprocket 6 I.

Shaft 54 is connected with a bevel gear 62 meshing with a bevel gear 63 attached to a shaft 64 journaled in bearing 65 supported by a bracket 66 supported by the base 50 (Figs. 17 and 18). Shaft 64 drives a sprocket 61 connected by a chain 68 (Fig. 9) with a sprocket 69 (Fig. 10).

Referring to Fig. 11, the sprocket BI is connected by a key 10 with a tubular shaft 1I journaled in roller bearings 12 and 13 supported by brackets 14 and 15 respectively attached to the base 50. connection with a shaft 16 by a key 11. Shaft 16 is journaled also in a bearing 18 supported by a bracket I35 attached te plate 48 and shaft 16 extends through a seal ring 80 retained by metal rings 19 and 19a. Shaft 15 carries a fixed plug portion 8| and a movable plug portion 02 which is urged away from plug portion 8| by a spring 83. The plug portions enter the core of a commutator and press it against .a disc 85 integral with a short'shaft S6 journaled in a roller bearing 81 which is retained by a plate 88 which screws 89 attach to the bar 43.

The shaft 16 is moved axially from the commutator engaging position shown in Fig. 11 by a cam 90 provided with slots 9| through which screws 92 pass for clamping the cam 90 to a hub 93 which a key 84 attaches to a cam shaft 95. As shown in Figs. wand 14, shaft 95 is journaled in roller bearings '96, supported by 4 brackets 91 mounted on base 50. Shaft 95 is driven bya gear 98, meshing with a gear 99 driven by a shaft I driven by sprocket 69. Shaft I00 is mountedin bearings 'IOI' supported by brackets I02 mounted on base 50, Fig. 14.

Referring to Fig. 11, cam 90 is engaged by a roller I03 pivotally supported by a pin I030. (Fig. 13) carried by a lever I04 which is pivotally supported by a pin Ia attached to a bracket I05.mounted on base 50. The forked upper end of the lever I04 supports rollers I06 which are received between flanges I01 provided by shaft 16. Shaft 16 is urged to the right by a spring IIO, the left end of which engages ,a retainer III integral with a screw II2 threaded through a plate II3 which is attached to brackets II4 (Fig. which are attached to the bracket 14. Anut I.I5 locks the screw H2 in. the desired position of adjustment. The right end of spring H0 is received by a retainer II6 having a stem II1 received by the inner race of a ball bearing II8 whose outer race is retained by :a cup II!) which a screw I20 attachesto the shaft 16. It is therefore apparent that the spring IIO urges the shaft 10 toward the right (Fig. 11) and the roller I03 into engagement with the cam 90.

The parts which are shown in Fig. 12 are substantially identical with those shown in Fig. 11, and the same reference numbers are applied to similar parts with primes, affixed. Therefore no further description of Fig. 12 is required except to state that shaft I00 (not shaft 95) drives cam 90.

Referring to Fig. 15, a cam I has slots I26 for receiving, screws I21 for attaching the cam I25 to a cam hub I28 driven by shaft 95. Cam I25 engages a roller I30 supported by a pin I3I carried by a lever I32 supported by a pin I33 supported by a bracket I34 attached to bracket I35 attached to plate 46. Bracket I35 supports aligned bushings I36 and I31 which receive a rod I38 having a reduced part I39 for receiving the bifurcated upper end I40 of the lever I32. The rod I38 is urged right and the roller I30 is urged left by a spring I4I located Within a Shaft H has a longitudinal spline 'by screws I61. I68 in a block I69 through which the rod I5I retainer I42 which screws I43 fasten to the bracket I35. The spring MI is confined between a screw plug I44 threaded into the retainer I42 and the left end of the rod I38. The construction shown in Fig. 16 is substantially the same as that shown in Fig. 15, therefore, similar parts are referred to by the same reference numbers with a afiixed. Cam I25a. is attached to the hub 93 which carries cam 90 (Fig. 14). Lever I32 is longer than lever I321; because the pin I38 is at a higher level relative to the base 50 than the pin I38a. Retraction of pin I36 to the left of plate 46 while pin I38a extends to the right of plate 46 allows a commutator to pass to the first test station. Advancing of pin I38 to the right of plate 46 holds back the commutators which are above the first station on the chute. While the pin I38 is so located, pin I30a is retracted to permit a commutator to descend to the second station. Pins I38 and I380. are adjacent the second station for similar purposes. The mechanisms, shown respectively in Figs. 19, 20- and Figs. 21, 22, 23, for operating the pins I38 and I38a', are like the mechanisms shown in Figs. 15 and 16 and similar reference numerals are used with primes afiixed. For example, cam I25 controls pin I38 (Fig. 19); and cam I25a. controls pin I38a (Fig. 21). Cam I25 is attached to a hub I28 driven by shaft I00. Cam I25a is attached to hub 93' which carries cam 90- and which is driven by shaft I00.

Referring to Figs. 24 through 27 the bracket I35 supports a. guide bushing I50 which receives a rod I5I, the lower end of which rests upon a roller I52 journaled on'a pin I53 carried by a lever I54 pivoted at I55 on a bracket I56 supported by a base 50. Lever I54 pivotally supports a roller I51 engaging a cam I58 having slots I59 through the screws I60 for attaching the cam to a hub IOI (Fig. 14) which is keyed to the shaft I00. A bracket I65 is attached to the bracket I35 and supports a plate I65a which supports'rods I65 (Fig. 24) which are retained The rods are guided by bushings passes, said block being retained by a nut I10 threaded on the rod. Springs I1I, which are confined by retainers I12 and I13 bearing respectively against the plate 55a. and the block I69, urge the rod'I5I downwardly and the roller I51 into engagement with the cam I58.

Block I69 (Fig. 24) carries a stud I which pivotally supports non-conducting arms I8I and I82 (Fig. 26) which respectively support metal brackets I83 and I84 pivotally supporting metal contact rollers I85 and I85 (Fig. '1) respectively for engaging adjacent bars of the commutator C. The brackets I83 and I84 are connected into the electrical circuit shown in Fig. 1. Springs I81 and I89 which engage the arms I81 and I82 respectively and a stud I90 attached to the block I69 urge the rollers against the commutator when the block I59 is lowered or against a stop pin I9I when the block is raised.

The mechanism (Figs. 283l) for operating block I69 at the second station (Fig. '7) is similar to the mechanism for operating block I69 and like parts are referred to by the same referencenumbers with primes affixed. Cam I58 is attached to a hub I6I driven by shaft I00 (Fig. 14). Block I59 (Fig. 31) supports similar nonconducting arms I8! and I82 supporting rollers I85 and I86 respectively supported by brackets I03 and I84 respectively which are connected into the electrical circuit. Block I69 carries another stud I94 supporting a non -conducting arm I95 supporting a metal bracket Hi6 carrying a contact when I91. When the block 169" is lowered as shown in Fig. 7, rollers I85, I86 and i9! engage the commutator. When the block. H59 is lifted, the arms IBI and [82 engage a stop pin l3! and the arm E95 engages a stop pin I98.

Referring to Figs. 4 to 6, the track section 4! comprises side plates 268' and 2G! and bottom plates 262, 263 and 254 which are spaced to provide openings 205 and 266. A splice plate 201 secured by screws 298 to plate 2&2 and by screws its to plate M unites the track sections. The lower one of the screws 2 it which secure the plate to plate c4 of section ie is threaded through a hole 2 in plate 266.

The openings 265 and 2% are normally closed by trap doors H5 and 216 respectively which are attached to hubs 2i! and 2l8 respectively pivotally supported by rods 2H? and 220 respectively supported by blocks 272i and 222 respectively (Fig. 6), which are attached as shown in Fig. 5, to plate Ziifl by screws 223 and dowels 22 2. The traps M5 and 2 H3 each have downwardly extending arms 2l5a and H60. supporting plates 225. and 226 attached respectively to springs 221 and 228 which respectively urge these plates clockwise toward the plungers 229 and 238 respectively of solenoids SI and S2 attached to plates 23! and 232 which are supported by brackets 233 and 234 respectively attached to the plates 26% and 28!. So long as these solenoids are deenergized,

the openings 2% and 2S6 are closed by thetraps Eli; and H6.

In case of a short circuit 01" the commutator the solenoid SI is energized and the rod 229 moves right thereby pushing against the bar 225 sufficiently to cause the center line of action of the spring 221 to be located to the right of axis of the rod 2L9 whereupon the trap 2H5 moves counterclockwise into the position 2l5 and its arm 2| 5a moves into the position 215a. The commutator rolls into the opening 285 and rests upon the arm 215w and the weight of the commutator causes the trap to return to normal position and the plunger of the solenoid. also to return to normal position because the solenoid had been momentarily energized and becomes deenergized as soon as the commutator is released from the second station. The commutator descends to bin for receiving shorted commutators.

In case of a ground between any of the oominutator bars and the commutator core, the solenoid S2 will be momentarily energized and the trap 2K6 will move to 216 and its arm 2l6a to 2 i to and the commutator will be discharged into bin for receiving grounded commutators.

If the commutator passes the short test and the ground test at the second station, the traps 2l5 and 2 it remain in normal position and the commutator rolls from the lower end of the chute into a bin for receiving good commute-tors. Just before leaving the lower end of the chute section H, the commutator engages an arm 246 of a counter 24! which is mounted on a bracket 242 attached to the plate 296.

Referring to Fig. 1, the electric motor M becomes operative upon closing of switch SW3 connecting it with a three phase A. C. circuit and by closing a switch SW 2 when a solenoid S3 is energized. Solenoid S3 is connected with wire 25% connected with wire 25! and is connected with wire 252 connected with a relay contact 253 6 I engaging. contact 254 of relay RE3 whichis connected with wire 255. Wires 2.51 and 255- are connected by switchSl withan alternating current source of: 110 volts. At station I where rollers [.85 and I86 engage the rotating commutator, volts A. C. is applied in order, to burn out any small particles of metal which might happen to lie against the mica insulators. and cause minute short circuits between adjacent bars. The necessary current is obtained from the secondary Tls of transformer Tl whose primary Tip is connected by wire 256 with wire 25i and with a contact 251 normally engaging a contact 2 58 of a thermal cutout relay 2% having a coil 25:? which is connected with wire 255. In case of an overload, the coil 259 will carry current sumcient to effect separation of the contacts 26?- and 258. Relay 268 may be set to operate to open at amps. thus protecting the transformerTl in case an abnormal current is drawn from its secondary as the commutator revolves at station I. The relay 269 is reset manually. The separation. of contacts 257, 258 interrupts a normal short circuit around coil RE-3c of relay RE3- which then seperates contacts 254, 253 and solenoid" S3 is deenergized' and the circuit to the motor M is disconnected and the motor stops. By closing switch SW5 for a brief time, the solenoid S3 isreenergizedand motor M will turn the commutator away from a dead short position so that thethermal relay 260 can be reset.

At station 2 the commutator is rotated for the short and ground tests. rent is applied to contact rollers I and I86 by the secondary T3s of a one to one ratio isolation transformer T3 whose primary T37; is con nected with wires 25! and 255. Secondary Tits is in series with winding 26! of relay RE! having contacts 262 and 263 In case of a short circuit between adjacent commutator bars, coil 26I will be energized and contact 262 will engage contact 263 thereby connecting solenoid Si with lines 264 and 265, thereby causing the trap 215 to move counterclockwise thereby effecting ejection of the shorted commutator at opening 265 in the chute or track.

For the ground test transformer T2 is provided. Its primary T210 is connected with wires 251 and 255. One end of its secondary T2s is grounded and the other end is connected with roller i531. If, during rotation of the commutator at station 2 any bar is grounded to the core connected with the shaft 1'6 which is grounded, current at 500 volts will flow through winding 210 of relay REZ, thereby causing its contact 2?! to engage contact 212 and solenoid S2 will be connected with wires 26d and 265. Trap 216 will then move counterclockwise. to effect ejection of the grounded commutator through the opening 206 in the track or chute.

The commutators may cease rotation at the station at such angular position that the relays RE! and RE'Z would be deenergized or the commutators may cease rotation leaving the relays energized. In any case, the relays RE! and REZ will be deenergized when the contact rollers are retracted. Therefore if either trap has been set for ejection of a commutator, the descent of the commutator from the chute restores the trap to normal position for supporting a commutator upon the chute if the commutator tests good. A commutator which passes the short testwill be retained by trap H5 and allowed to pass to trap 216, which will be tripped only in case the commutator fails to pass the ground For the short test cur test. If the commutator passes both tests, neither trap 2I5 nor trap 2 I6 is tripped.

Lamp LI, connected with transformer secondary T38, indicates that switch SWI has been closed and that the apparatus is ready for the short test. Lamp L2 which is connected with wires 264 and 265 burns to indicate that switch SW2 has been closed and that solenoids SI and S2 are ready to operate if relays REI and REZ respectively are closed. Lamp L3 burns if thermal relay 2% opens and indicates that the motor M has stopped as result of excessive current in the primary of transformer TI when burning ofi metal from the commutator the burning draws excessive current from the secondary of transformer TI.

Referring to Fig. 32, lines AB-C-D-EF show action of cams Ia and I25a which control pins I3iia and I38a at the first and second stations respectively. Lines GHJK-L--M show action of cams I25 and I25 which control pins I38 and 133' at the first and second stations respectively. At C-D pins I38a and I38a are retracted to allow the commutators to roll down the chute away from the stations while the pins I38 and I38 are advanced to prevent descent of commutators above the stations. While between and 115 (DE) the pins I38a and I38a are advancing, pins I38 and 38 are retracting between to (I-IJ) to permit commutators to roll into stations 5 and 2 respectively. At L, the pins I38 and I38 are advanced to separate the commutators at the stations I and 2 respectively from those commutators which are above the stations.

Lines I\TOPQR represent the action of cams Q0 and 90' which advance and retract shafts l6 and 16 respectively. At 0 to P these shafts are retracted. At Q to R (350) the shafts are rotating the commutators.

Lines STUVW represent the action of cams I58 and I53 in raising and lowering the rollers which engage the commutators while they rotate at stations I and 2. At TU, the test rollers are up. At V (190) to W (340) the test rollers engage the commutators. They engage the commutators when the commutators begin to rotate and they leave the commutators just before the cornmutators cease rotation at the stations.

From the foregoing description, it is apparent that the commutator inspecting apparatus provides an inclined chute or track down which a commutator rolls past two stations. At station #I, the commutator is caused to stop and to be rotated axially while electric current is applied for burning off metal particles which might provide conducting paths between commutator bars, or between any bar and the commutator core. The voltage between rollers I85 and I88 is 25 volts, and the voltage between roller I85 and ground is 50 volts. The commutator is then released and rolls to station #2 where it is caused to stop and to be rotated axially while electric currents are applied thereto to detect shorts between bars not removed by burning and to detect a ground between a bar and the commutator core not removed by burning. Traps forming parts of the chute are tripped respectively in response to detection of shorts and grounds for the purpose of causing the commutator to drop through the track into suitable bins after the commutator is permitted to descend from the second station. If the commutator is free of shorts and grounds, the traps are not tripped and the commutator rolls to the end of the chute and drops into a bin for receiving good commutators.

When the apparatus is used for testing commutators having riser bars, it is desirable to use a feeding station above the first or burn-out station.

Referring to Figs. 33-35, the upper end of the track bar 44 is spliced to an extension track bar 300 by means of a plate 31' secured by screws 302 and also by a splice bar 385 secured by screws 3% which pass through a spacer plate 304 and a bar 3% extending below the bar 305. Screws 301 attach to plate 303 a plate 3&3 to which a cylinder 3H1 is attached by screws 309. Cylinder '3I0 contains a piston having a rod SI I connected by a coupling 3 I2 with a rod 333 which has a notch to provide a fiat 3M and which is guided by a bracket 3I5 which screws Eit attach to the plate 3M. Screws 3!! attach to bracket 315 a plate 3M3 which is located close to the fiat 3M thereby preventing rotation of the rod 3I3.

A pin 3 I 9 connects rod 3 It with a bar 320 which screws 32I passing through slots 322 in bar 32!; attach to a commutator release bar 323 adapted in its down position (Fig. 33) to extend between commutators represented by dot-dash circles C and having riser bars represented by dot-dash circles B. When the bar 323 is in the down position 323', the right commutator cannot gravitate down the track bars 3M, but the left commutator is free to move. When fluid pressure is applied to the lower end of cylinder 3 I0 to cause the rod 3 I3 and the bar 323 to move up to release a commutator immediately to the right, it is necessary to provide a stop to prevent movement of the released commutator further than the position that the left commutator had occupied. For this purpose, a pin 324 attaches to the rod 3I3 a bar 325 having a hole therein through which a rod 325 extends and also through a hole in the track extension 300. The rod 326 is located in the desired vertical position by nuts 32? and 328 threaded on the rod and screwed against the bar 325. The cylinder 3 I 3 is controlled by a valve 330 which is spring actuated into the status of admitting pressure fluid to the lower end of the cylinder 3H! while the upper end is connected with exhaust. When a solenoid 33! is energized the valve will be conditioned to admit pressure fluid to the upper end of the cylinder 3Ifi while the lower end is connected with the exhaust. The solenoid 33I is controlled by a switch 332 which is operated by member I63 (Figs. 7 and 24) through a lever 335. When member I59 moves up after the burning operation at station I, the pin I38a is retracted to release the commutator which had been subjected to burning current, and pin I38 is advanced to prevent a commutator from descending to station I from a position above that pin. When member I69 moves up, lever 335 moves up to close switch 3,32 and the solenoid 33I is energized so that valve 330 is conditioned for causing pressure fluid to be admitted to the upper end of cylinder 3I0, whereupon the rod 326 and the bar 323 move down respectively from positions 326' and 323' so that a commutator will be released by the feeder shown in Fig. 33 while another commutator will be retained by this feeder. When bar 323 moves down, it separates the contiguous commutators so that their riser bars will become separated, and the gravitation of the lower commutator will not be interfered with by the upper commutator.

While the embodiment of the present invention 9, as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow. What is claimed is as follows:

1. Apparatus for testing commutators having tubular, metal cores comprising an iinclined chute down which the commutators roll, means for arresting movement of a commutator at a test station intermediate the ends of the chuteand then for releasing the commutator after the test, a metallic, rotatable member for engaging the core of the commutator at the test station, means for advancing and retracting the rotatable member, a pair of contacts for engaging,adiacentfcommutator bars, a third contact for engaging the commutator bars, means for advancing and retracting the'contacts, mechanism for operating said means in recurrent sequence, t vo'traps lo cated below the test station and each normally permitting the commutator to pass down the chute and each movableto a position for eiiecting removal of the commutator from the chute, electromagnets respectively for operating said traps, a current source for said electromagnets, relay switches respectively for connecting the magnets with their current source, second and third current sources, a circuit including the second source, the coil of one of the relay switches and the pair of commutator engaging contacts, and a circuit including the third source, the coil of the other relay switch, the third commutator engaging contact and a ground circuit to the source through the commutator core and rotatable core engaging members, whereby the traps are moved respectively in response to short circuit between bars and ground of a bar on the commutator core.

2. A commutator testing apparatus comprising an inclined chute down which the commutators roll, two devices respectively for arresting movement of a commutator at a first or burnout station and at a second or test station intermediate the ends of the chute and then for releasing the commutator, a rotating member at each station for engaging the commutator to rotate it, a device at each station for advancing and retracting the rotating member, pairs of contacts at each station for engaging adjacent com mutator bars, a device at each station for ad-= vancing and retracting the contacts, mechanism for operating said devices in recurrent sequence, a current source connected with the pair of contacts engaging the commutator at the first Sta-- tion for burning metal particles lodged at the surface of the commutator between commutator bars, a second current source connected with the pair of contacts engaging the commutator at the second station, a trap below the second station normally permitting the commutator to pass c down the chute and movable to a position for effecting removal of the commutator from the chute, and means responsive to flow of current from the second current source between adjacent bars for causing the trap to move into commutator removing position.

3. A commutator testing apparatus comprising an inclined chute down which the commutators roll, the commutators having metallic tubular cores insulatingly supporting commutator bars, a device for arresting movement of a commutator at a ground-test station, a metallic, rotating member at said station for frictionally engaging the interior surface of the commutator core to rotate the commutator, reciprocating mwwwn w 4 me Man...

means for advancing and retracting the member into and out of engagement withthe commutator core, a current source connected with the mem her, a contact connectediwith" the sourceand engageable with the commutatorgbars as they rotate, a trap below said station normally open for permitting the commutator to pass down the chute and movable to another'positionforeiiecting removal of the commutator from the, chute, and electrically operatedmeans responsiveto now of current fromsaid sourcebetweenaba'r and the core of the commutator through saidmemher for causing the trapto moveintosaid-another position for removing the commutator 4. A commutator testing apparatus comprising aninclined chute downwhich the commutators roll, a 'teststation, means at said station. for arresting movement of the commutatonmeans for rotating the commutator while at the test station, a current'sourc'e, a circuit for connecting the current source with "pa'rtsof the commutator which, in' a good commutator are electrically disconnected, said" circuit including an'electromagnet whichis momentarily energiz'edii commutator parts connectedinto said circuitduring rotation of'the commutator are electricallyconnected, said chute having a commutator discharge opening below the test station, two mechanically connectable movable elements, one for normally closing the opening and the other normally extending below the opening, and operating means rendered efiective by momentary energization of the electromagnet for opening the first trap element to extend above the chute to block movement or" the defective commutator whereby the second trap element receives the blocked commutator, the weight of the commutator causing the elements to return to normal position in consequence of which the commutator falls from the second element.

5. A commutator testing apparatus comprising an inclined chute down which the commutators roll, a test station, means at said station for arresting movement of the commutator, means for rotating the commutator while at the test station, a current source, a circuit for connecting the current source with parts of the commutator which, in a good commutator are electrically disconnected, said circuit including an clectromagnet which is momentarily energized if commutator parts connected into said circuit during rotation of the commutator are electrically connected, a trap below the test station and comprising a pivoted lever having an arm normally located in position to close commutator discharge opening in the chute so that the com mutator will normally pass down the chute, said lever having a second arm angularly displaced from the first arm, a spring connected with the lever and normally biased to hold the lever in normal position and biased by virtue of movement of the first lever arm a certain distance above the chute to cause the first arm to move further into commutator blocking position and the second arm to move into commutator receiving position and an armature moved in response to momentary energization of the electromagnet for moving the lever to locate the first arm said certain distance above the chute, the defective commutator moving against the first arm and engaging the second arm, the weight of the commutator efiecting return of the lever to normal position in consequence of which the commutator falls from the second arm.

6. In a commutator testing device, the com- 11 bination comprising an inclined chute down which commutators can roll, a device for feeding commutators singly from a supply at the upper end of the chute, a station at which a commutator stops during its passage down the chute, upper and lower commutator engaging pins adjacent said station and extendable alternately into the path of movement of the commutator, means for retracting the lower pin to release a commutator from the station while advancing the upper pin to retain a commutator before arrival at the station and vice versa, to advance the lower pin while retracting the upper pin, a member movable laterally of the commutator, a contact carried by the member into engagement with the commutator for the purpose of the function to be performed at the station, means for advancing and retracting the member, a mechanism for operating the pin moving means and the member moving means in timed relation so that the member is advanced toward the commutator when the lower pin is advanced and the upper pin is retracted and, vice versa, so that the member is retracted and the lower pin is retracted and the upper pin is advanced, and means respon- 12 sive to retraction of the member for conditioning the feeding device for the release of a commutator from the supply at the upper end of the chute.

RUPERT C. WHELCHEL.

REFERENCES CITED The following references are of recordin the file of this patent:

UNITED STATES PATENTS Number Name Date 939,109 Switzer Nov. 2, 1909 1,372,945 Cullin Mar. 29, 1921 1,656,887 Goldsmith Jan. 17, 1928 1,690,345 Poole Nov. 6, 1928 1,842,810 Whelchel Jan. 26, 1932 1,971,426 Poole Aug. 28, 1934 2,270,428 Flint Jan. 20, 1942 2,383,300 Benson Aug. 21,1945 2,427,672 Haydock Sept. 23, 1947 FOREIGN PATENTS Number Country Date 348,311 Great Britain May 14, 1931 pwe 

